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Hire Dr. Marguta R.

Romania

Profile Summary

My main areas of research comprises computer modeling and simulations in nanostructured materials (zeolites), the understanding of complex systems at a molecular level using molecular simulations (Monte Carlo, Molecular Dynamics) with particular emphasis on phase equilibrium of model systems which exhibit liquid crystal phases. Another research line at the crossing between applied mathematics, statistical physics and epidemiology captured my attention, with special interest on the spread of infectious diseases on large geographical areas, complexity and stochastic effects in disease dynamics. The main goal of my PhD thesis was to determine the phase diagram of different model systems which exhibit liquid crystal phases. The model used is characterized by purely repulsive intermolecular interactions (Hard Gaussian Overlap), and the inclusion of attractive (Square Well) interactions obtaining the HGOSW model. In addition to the isotropic(fluid) and solid phases, this models exhibit phases with intermediate order ,plastic, nematic, smectic, which makes them interesting from technological point of view. For this purpose I have setup a full range of non-trivial simulation techniques for the calculation of free energies of fluid and solid phases from computer simulations, including thermodynamic integration, parametric integration, Einstein crystal and particle-insertion method. I have made use of a general perturbative approach for the computation of the first-order derivative with respect to an arbitrary parameter. As a postdoc researcher I got experience in molecular simulation of lattice model under confinement. I have studied the Lebwohl-Lasher model of nematic liquid crystals in confined geometry through Monte Carlo simulations together with cluster algorithms. This model is important to understand the formation of nematic phase in mesogenic materials, providing quantitative information about nematic properties. In the Monte Carlo algorithm two types of moves were considered, one- particle orientational moves consisting in the standard algorithm for linear molecules, and cluster moves performed by means of usual bonding criteria. Simulations have been performed with the view to locating accurately the phase transition. Two types of surface conditions have been imposed, namely symmetric and asymmetric walls. For symmetric walls we established a lower limit for the pore width at which the capillary isotropic-nematic transition takes place. Complex materials with a well defined microporous geometry, such as zeolites, are important subject from the technological standpoint, in particular in petrochemical processes cracking, separation of linear and branched alkanes, etc.. In one of the research projects I was working in, my main research was focused on molecular simulation study of adsorption of alkanes and aromatic molecules in this complex materials (zeolites), using Configurational Bias Grand-Canonical Monte Carlo technique. In the study of adsorption of aromatic molecules (benzene, toluene), I have implemented the Cavity/Energy Bias Grand-canonical Monte Carlo technique. Analysis of simulation snapshots, angular distribution functions and intermolecular correlation, was performed in order to gain a microscopic view of the adsorption process and a better understanding of the packing effects observed in experiments. In the last years I was working in a research project on the impact of human mobility on the dynamics of infectious diseases. With this purpose we propose a computer model which combines three levels of description, population level (gridded description of human settlements), mobility level which describes the movement of individuals between gridd units, and the epidemiological model which describes how the disease evolves. The mobility of individuals is described by the Radiation model, which was seen to fit existing human mobility data. Depending on the disease under study an epidemiological model is considered, SIR and SEIR epidemiological models were considered for measles, and the two strains model for Dengue fever study. We applied the computational model to perform individual based simulations for different geographical areas British Isles, Thailand. We studied synchronization and periodicity in our detailed description and its relation with the time series observed at the global level. The model can be modified to permit equation based simulations of co- evolution of viral strains (flu) in a global (world-wide) setting.

Subject Matter Expertise

• ☆ Condensed Matter Physics
• ☆ Microscopy
• ☆ Cluster Analysis
• ☆ Infectious Disease
• ☆ Dengue
• ☆ Epidemiology

Services

• Writing
• Data & AI

Work Experience

postdoctoral fellow

University of Lisbon

March 2012 - March 2015

hired on contract

Consejo Superior de Investigaciones Cientificas

January 2010 - December 2011

postdoc

Universidad Autonoma de Madrid

April 2009 - December 2009

Education

postdoc (Centro de Matemática e Aplicações Fundamentais, Mathematical Biology Group)

University of Lisbon

December 2014 - July 2015

postdoc (Condensed Matter Physics, Physics of Bilogical Systems Group)

University of Lisbon

March 2012 - September 2014

hired on contract (Statistical Mechanics and Condensed Matter)

Consejo Superior de Investigaciones Cientificas

February 2010 - December 2011

postdoc (Department of Condensed Matter Physics)

Autonoma University of Madrid

May 2009 - December 2009

PhD in Physics (Department of Applied Physics)

University of Huelva

January 2005 - January 2009

Master in Physics (Faculty of Physics)

Al. I. Cuza University

October 2002 - September 2004

degree in mathematics-physics (Faculty of Mathematics)

Al. I. Cuza University

October 1998 - June 2002

Certifications

• Certification details not provided.

Publications

JOURNAL ARTICLE

(2015). Impact of human mobility on the periodicities and mechanisms underlying measles dynamics. Journal of Royal Society Interface, March 2015 Volume: 12 Issue: 104.

(2011). Molecular simulation and adsorption studies of n-hexane in ZSM-11 zeolites. Microporous and Mesoporous Materials Volume: 142 Issue: 1 Pages: 258-267 Published: JUN 2011.

(2011). Theory and simulation of the confined Lebwohl-Lasher model. Physical Review E Volume: 83 Issue: 4 Published: APR 5 2011.

(2008). Study regarding the water pollution in Romania and Spain. : Romanian Journal of Physics Volume: 53 Issue: 1-2 Pages: 157-163 Published: 2008.

(2007). System-size dependence of the free energy of crystalline solids. Journal of Chemical Physics Volume: 127 Issue: 15 Published: OCT 21 2007.

(2006). Revisiting McMillan's theory of the smectic A phase. Journal of Physics-Condensed Matter Volume: 18 Issue: 46 Pages: 10335-10351 Published: NOV 22 2006.

CONFERENCE PAPER

(2014). Human mobility and measles. Proceedings of the 14th Conference on Computational and Mathematical Methods in Science and Engineering, CMMSE 2014.

(2014). Human mobility and the dynamics of measles in large geographical areas. Proceedings of the 14th European Conference on Complex Systems, ECCS 2014.

(2013). Stochastic amplification and childhood diseases in large geographical areas. Proceedings of the 13th Conference on Computational and Mathematical Methods in Science and Engineering, CMMSE 2013.